The power condition in the U.S. is unstable. The AC power that runs your home theater is constantly in a state of flux. Sometimes there's too much voltage, sometimes not enough. Power can become so unstable that you can actually see it happening, like when the lights in your house suddenly begin flickering. During the worst case scenario, when your equipment turns back on, a power spike can be 200-300 volts. Your expensive electronic home theater components are extremely sensitive to any increase in voltage, and can be severely damaged or destroyed by these unseen fluctuations in power. And, when it comes to surge protection, remember, it's all or nothing... every possible pathway for surges (including coax and phone lines) must be protected. The Monster Power Home Theatre PowerCenter HT 850 is equipped with Monster's fast-acting high capacity Multiple SurgeGuard circuitry, which instantly detects any voltage surge or spike and immediately suppresses it before it can even reach your components. Plus, the HT 850 has been designed with 1 set of coaxial connections so you can hook up your HDTV or cable box for total home theater system protection. Best of all, unlike other surge protectors, Monster's ultra-low-loss RF circuitry provides maximum protection with virtually no signal loss.